摘要
通过键合不同数量的H2 PO-4 离子构造了H4P2 O2 -8和H4P4O8-1 6 两种阴离子集团 .利用密度泛函理论对它们的构型进行优化并计算其振动频率和喇曼散射效率 .测量了固 -液界面边界层的喇曼光谱并与理论计算结果进行对比分析 ,进一步研究了阴离子集团的结构、聚合及脱水等过程 .实验和理论研究均表明阴离子二聚体是KDP晶体的生长基元 ,他们在固液界面将进一步形成多聚体分子集团 ,而离子集团的脱水过程则发生在距KDP晶体表面约 5 0 μm的固 -液界面边界层中 .随着生长层向界面的推进 ,这些分子集团将变得越来越有序 .本文的研究结果对确定晶体生长界面动力学过程。
Two kinds of anion clusters, i.e., H4P2O82- and H4P4O168- are constructed, by bonding two and four H2PO4- anions. The optimized configurations, vibrational frequencies and Raman activities of H2PO4- H4P2O82- and H4P4O168- are obtained by using density functional theory. The Raman scattering spectra in the solid-liquid interface boundary layer are measured, and compared with those of theoretical calculation for studying the configuration and the processes of polymerization and dehydration etc. Both the experimental and theoretical results indicate that dimmer clusters may be the growth units in crystal growth, which can polymerize further and form polymer cluster on the solid-liquid surface. The dehydrating process of dimmer and polymer clusters starts at a growth layer about 50 mum apart from the solid-liquid surface of the KDP crystal. With approaching to the crystal-liquid surface, the molecular cluster becomes more and more orderness. The results obtained are of significance in identifying the surface kinetics process and developing more sophisticated crystal growth theories.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2003年第2期181-185,共5页
Acta Chimica Sinica
基金
国家自然科学基金 (No.2 0 0 760 0 1
2 0 2 360 1 0 )资助项目
